Chances of having a missed miscarriage at 15 weeks?

This is my first baby and I had a ectopic and a miscarriage so sometimes I get traumatized about losing this one. By reading all these stories online how some women lost their babies at 20 weeks and had no symptoms and they couldn’t find a heartbeat or some say that they lost their baby at 16 and baby stopped growing at 15 etc just makes me go crazy and i think how is that possible to happen in the 2nd trimester? I need to stop reading this stuff but I can’t half of me can’t even believe it. Every appointment has been great for me so far my baby girl has a strong heartbeat blood tests came back good last time I did a ultrasound she was very active on the screen sucking her thumb heartbeat was at 170 and now I’m terrified at my 16 week which is next week all of that would be gone. I’m 15 weeks and sometimes I’m worried cause all of my pregnancy symptoms are gone I’m not having any bleeding or bad cramping. Some people say it’s the placenta taking over but what if something is wrong ugh I need help can someone help me stop feeling this way I can’t lose my baby girl 😪